Search PubMed⌕ Search

Biomedical subjects

Jie Yang

Publications and source records attributed to Jie Yang.

197 records · Page 11Linked to original sources
PubMed2002

Chlamydia trachomatis infection inhibits airway eosinophilic inflammation induced by ragweed.

While much progress has been achieved in controlling infectious diseases, there is a startling increase in the prevalence of allergic disorders in developed countries. Previous studies using experimental murine models of asthma have demonstrated that mycobacterial infections are capable of suppressing asthma-like reactions induced by ovalbumin (OVA). Using a different intracellular bacterium, Chlamydia trachomatis mouse pneumonitis (MoPn), we examined the effect of infection on the development of allergic responses to a common natural airborne allergen, ragweed (RW). The data showed that airway eosinophilia induced by ragweed sensitization/challenge was significantly reduced in MoPn-infected mice. MoPn-infected mice also exhibited significantly lower levels of allergen-driven Th2 cytokine production, namely IL-4, IL-5, IL-10, and IL-13, following ragweed exposure in comparison with those treated with ragweed only. Additionally, the production of eotaxin, a C-C chemokine for eosinophil chemoattraction following RW exposure, was significantly reduced in the lungs of MoPn-infected mice. However, MoPn infection did not reduce the levels of RW-specific IgE and IgG1 production in the sera, nor did it diminish the level of total serum IgE. These data provide evidence that the suppression of the allergic airway inflammation induced by a common environmental allergen is attainable through intracellular bacterial infection.

Allergens↗
PubMed2002

Conservation of Epstein-Barr virus cytotoxic T-cell epitopes in posttransplant lymphomas: implications for immune therapy.

Posttransplant lymphoproliferative disease can be treated by the infusion of Epstein-Barr virus-specific cytotoxic T lymphocytes, which were raised against lymphocytes immortalized with a laboratory strain of Epstein-Barr virus (B95.8). Whether the immunodominant epitopes in B95.8 are shared in virus from tumors will affect the general applicability of this therapy. We have characterized the viral strain and the sequence of commonly recognized cytotoxic T-lymphocyte epitopes in 25 posttransplant lymphoproliferative disease specimens from 19 patients. Type A virus was present in 24 of 25 specimens. No variation in two LMP2A epitopes and a few variations mostly outside the targeted epitopes or silent in three EBNA3C epitopes were found, with one variation (Arg to Lys) detected in an EBNA3C epitope in 12 of 24 tumors. However, cytotoxic T lymphocytes to B95-8-derived EBNA3C peptides specifically lysed both B95-8 and the Lys-variant peptide-loaded target cells, although with less efficiency. These results suggest that adoptive immunotherapy using cytotoxic T lymphocytes expanded with B95.8 stimulators or vaccine strategies using B95.8-derived sequence will generally target Epstein-Barr virus strains present in posttransplant lymphoproliferative disease tumors.

Amino Acid Sequence↗
PubMed2002

Molecular forces for the binding and condensation of DNA molecules.

Atomic force microscopy has been used to investigate the binding between a double-stranded DNA and bilayers of cationic lipids and zwitterionic lipids in low ionic-strength solutions. The binding of a DNA molecule to freshly cleaved mica surface in solution has also been measured. The binding of DNA molecules to cationic lipid bilayers has a minimal strength of approximately 45 pN. On zwitterionic lipid bilayers and mica surface, the minimal binding strength is approximately twice that value. The binding also has a dynamic nature, with only a certain percentage of recorded force curves containing the binding characteristics. Divalent Mg(2+) ions enhance the binding by increasing that percentage without any effect on the binding strength. We have also observed a long-range attraction between DNA molecules and cationic lipid bilayers with a strength much larger than the minimum force and a range well over 50 nm, possibly related to the driving force responsible for the two-dimensional condensation of DNA.

Binding Sites↗
PubMed2002

Mycobacterial infection inhibits established allergic inflammatory responses via alteration of cytokine production and vascular cell adhesion molecule-1 expression.

Our previous studies, as well as those of others, have demonstrated that local or systemic Mycobacterium bovis bacille Calmette-Guérin (BCG) infection can inhibit de novo allergen-induced asthma-like reactions, but the effect of this infection on established allergic responses is unknown. The aim of this study was therefore to examine the effect of mycobacterial infection on established allergy in a murine model of asthma-like reaction. Mice were sensitized with ovalbumin (OVA) in alum followed by infection with BCG and subsequent intranasal challenge with the same allergen. In some experiments, mice were sensitized with OVA followed by intranasal challenge with OVA and then given BCG infection with subsequent rechallenge with OVA. Mice without BCG infection but treated with OVA in the same manner, were used as a control. The mice were examined for immunoglobulin E (IgE) response and eosinophilic inflammation, mucus production, cytokine/chemokine patterns and adhesion molecule expression in the lung. The results showed that postallergen BCG infection suppressed the established airway eosinophilia and mucus overproduction, but not IgE responses. The inhibition of asthma-like reactions by BCG infection was correlated with a shift of allergen-driven cytokine production pattern and, more interestingly, with a dramatic decrease of vascular cell adhesion molecule-1 (VCAM-1) expression in the lung. These findings suggest that intracellular bacterial infection can inhibit established allergic responses via alteration of local cytokine production and the expression of adhesion molecules.

Animals↗
PubMed2002

Rapid assessment of trachoma in Hainan Province, China: validation of the new World Health Organization methodology.

This study was undertaken to validate a WHO methodology for the rapid assessment of trachoma. Fourteen villages were chosen by random sampling in two counties in Hainan Province, China. For the rapid assessment, trichiasis patients were identified, 50 children ages 1-10 years were examined for active trachoma, and information was collected on community access to services and community risk factors. To validate the methodology, a prevalence survey was undertaken simultaneously in the same villages. For the prevalence survey, 2428 people from 1606 households in the 14 villages were chosen by random sampling. Very little active trachoma was found by either method, although the rates of trichiasis were more substantial. Ranking of the villages by the two methods for trichiasis was highly correlated (Spearman's correlation coefficient = 0.60, p = 0.02). For active trachoma, the Spearman's correlation coefficient for the ranking of villages by the two methods was 0.40 and not significant (p = 0.14), suggesting that a correlation this close may have been seen by chance alone. The observational data showed all the villages to be at risk of active trachoma (due to poor environmental hygiene conditions), suggesting that this aspect of the WHO methodology overestimates the risk for active trachoma. We conclude that, with the exception of the community assessment of risk, this rapid assessment methodology is a valid tool for the assessment of trichiasis and possibly of active trachoma in rural communities, although the level of active trachoma in this study was too low to effectively validate that aspect of the methodology.

Child↗
PubMed2002

[Classification of genotyping hepatitis B virus with multiplex PCR].

OBJECTIVE: To establish a simple and practicable method to identify the different genotypes of hepatitis B virus (HBV). METHODS: Based on the alignment of 114 complete nucleotide sequence for HBV DNA of different genotypes, the specific sequence of each genotype was found. Six primer sets were designed for each of the six genotypes according to the genotype-specific sequence, and used separately for PCR. The genotype of HBV was identified according to the positive result of PCR. Three primer sets for B, C and D genotypes were added into a single tube for PCR reaction, and HBV was genotyped according to the length of the amplified DNA. RESULTS: There was no difference in the genotyping result of PCR by single or multiplex primers, which was identical to the PCR-RFLP method. CONCLUSIONS: This multiplex PCR method is simple, precise, sensitive, and easy to use.

DNA Primers↗
PubMed2002

[Application of multiplex PCR in genotyping of hepatitis B virus prevailing in Guangdong Province of China].

OBJECTIVE: To establish a convenient method for the genotyping of hepatitis B virus (HBV) using multiplex PCR. METHOD: Based on the alignment of 114 complete nucleotide sequences of HBV DNA belonging to different genotypes, acquired from the GenBank, genotype-specific sequences were identified according to which 6 pairs of primers were designed corresponding to each genotype. Subsequent genotyping of HBV was performed using these primers that were added, either alone or in conjunction with others, into a multiplex PCR reaction tube, and HBV genotype was determined according to the length of amplified DNA. RESULT: The genotyping result of multiplex PCR was consistent with that produced by PCR- restriction fragment length polymorphism as established by Lindh. We found in this study that among the HBV carriers in the vicinities Guangzhou of City, about 45% belonged to B genotype, 38.75% to C genotype and 16.75% to D genotype. CONCLUSION: This multiplex PCR method is simple, convenient and more differential.

China↗
PubMed2002

[Data mining in diagnostic knowledge acquisition from patients with brain glioma].

In order to correctly predict the malignant degree of brain glioma, three data mining algorithms: multi-layer perceptron network(MLP), decision tree, and rule induction are adopted to acquire diagnostic knowledge from patients with brain glioma cases. Totally 280 cases are collected, and some of them contain missing values. Preprocessing is taken to make them applicable to all three algorithms. Performance comparisons are carried out with a 10-fold cross validation test. Although the result of MLP is hard to be understood and cannot be applied directly, its reliability and accuracy are the highest when only a few hidden nodes are involved. Unlike MLP, both decision tree and rule induction use attribute-value pairs to represent diagnostic knowledge derived from treated cases. These could improve both the understandability and applicability of their results. When compared with rule induction, the inherent restriction in structure makes decision tree more efficient in decision-making but meanwhile hurts its simplicity, accuracy, and reliability. For testing samples, results of all these algorithms can achieve accuracy rate over 80%, which satisfies the basic requirement of neuroradiologists. If diagnostic accuracy rate is the main factor to be considered, MLP with only a few hidden nodes is the best. If the result is expected to be further checked or evaluated, rule induction will be the best algorithm. This work proves that data mining techniques can be used to obtain valid diagnostic knowledge from brain glioma cases and make computer aided diagnosis system in this field feasible.

Algorithms↗
PubMedDate not supplied

Male hormonal contraception: suppression of spermatogenesis by injectable testosterone undecanoate alone or with levonorgestrel implants in chinese men.

Monthly injections of testosterone undecanoate (TU) act as a male contraceptive by reversibly suppressing spermatogenesis to azoospermia or severe oligoazoospermia in 95% of Chinese men. In 5% of Chinese men, however, monthly TU administered alone fails to suppress spermatogenesis into contraceptive ranges, or sperm "rebound," leading to occurrences of pregnancy during treatment. Since combinations of progestins and androgens are associated with greater degrees of sperm suppression in white men, we hypothesized that the combination of TU and the progestin levonorgestrel (LNG) would result in improved spermatogenic suppression in Chinese men. Sixty-two healthy Chinese men were randomly assigned to one of the following 3 regimens: group I (n = 21) received 4 LNG rods (75 mg each), which were followed 4 weeks later by 500 mg of TU by intra-muscular (IM) injection every 8 weeks for 24 weeks; group II (n = 20) received 4 LNG implants, which were followed 4 weeks later by 1000 mg of TU by IM injection every 8 weeks for 24 weeks; and group III (n = 21) received TU 1000 mg by IM injection every 8 weeks for 24 weeks. Sperm counts, serum testosterone (T), luteinizing hormone, follicle-stimulating hormone, and LNG were measured every 2 weeks before, during, and after treatment. During treatment, group II demonstrated a trend toward a greater attainment of azoospermia than groups I and III (90% vs 62% [group I] vs 67% [group III]; P =.09). Attainments of either azoospermia or oligozoospermia (sperm density, <3 x 10(6)/mL) were 95%, 100%, and 86% for groups I, II, and III, respectively (P >.05 for comparisons between groups). Spermatogenesis in all subjects returned to the normal range after the implants were removed. No serious adverse events and no significant changes in serum chemistry occurred during the study. These results demonstrate that the combination of IM injections of high-dose TU every 2 months and LNG implants is associated with marked suppression of spermatogenesis in Chinese men. The combination of high-dose TU every 2 months and LNG implants is a promising candidate for future large-scale efficacy studies of hormonal male contraception in Chinese men.

Absorbable Implants↗
PubMedDate not supplied

Highly accurate and consistent method for prediction of helix and strand content from primary protein sequences.

OBJECTIVE: One of interesting computational topics in bioinformatics is prediction of secondary structure of proteins. Over 30 years of research has been devoted to the topic but we are still far away from having reliable prediction methods. A critical piece of information for accurate prediction of secondary structure is the helix and strand content of a given protein sequence. Ability to accurately predict content of those two secondary structures has a good potential to improve accuracy of prediction of the secondary structure. Most of the existing methods use composition vector to predict the content. Their underlying assumption is that the vector can be used to provide functional mapping between primary sequence and helix/strand content. While this is true for small sets of proteins we show that for larger protein sets such mapping are inconsistent, i.e. the same composition vectors correspond to different contents. To this end, we propose a method for prediction of helix/strand content from primary protein sequences that is fundamentally different from currently available methods. METHODS AND MATERIAL: Our method is accurate and uses a novel approach to obtain information from primary sequence based on a composition moment vector, which is a measure that includes information about both composition of a given primary sequence and the position of amino acids in the sequence. In contrast to the composition vector, we show that it provides functional mapping between primary sequence and the helix/strand content. RESULTS: A set of benchmarks involving a large protein dataset consisting of over 11,000 protein sequences from Protein Data Bank was performed to validate the method. Prediction done by a neural network had average accuracy of 91.5% for the helix and 94.5% for the strand contents. We also show that using the new measure results in about 40% reduction of error rates when compared with the composition vector results. CONCLUSIONS: The developed method has much better accuracy when compared with other existing methods, as shown on a large body of proteins, in contrast to other reported results that often target small sets of specific protein types, such as globular proteins.

Amino Acid Sequence↗
PubMedDate not supplied

Semiempirical quantum chemical method and artificial neural networks applied for lambdamax computation of some azo dyes.

The maximum absorption wavelengths of 31 azo dyes have been calculated by two comprehensive methods using the semiempirical quantum chemical method, PM3, and the weight decay based artificial neural network (WD-ANN) or the early stopping based artificial neural network (ES-ANN). The average absolute errors of WD-ANN and that of ES-ANN are 10.07 nm and 12.40 nm, respectively. These results are much better than the results using ZINDO/S with the default value (0.585) only.

Journal Article↗
PubMedDate not supplied

Y-STR polymorphisms among five Chinese minorities, Mosuo, Mongolian, Naxi, Pumi and Tibetan, in Yunnan Province, PR China.

Two hundred and thirty samples from five minority populations resident in Yunnan Province, PR China (the Mosuo, Mongolian, Naxi, Pumi and Tibetan communities) were analysed at eight polymorphic Y chromosome short tandem repeats (Y-STRs) loci. A total of 59 alleles were identified, with the largest number (n = 44) in the matriarchal Mosuo community. Two or three Y alleles were specific to each population. One hundred and thirty-five haplotypes were constructed, with 45 haplotypes in Tibetans, 34 in the Mosuo, 29 in Mongolians, 26 in the Pumi and 17 in the Naxi. The Tibetan and Mosuo peoples were closest in the neighbour-joining tree, whereas the Mongolians differed from the other four populations, reflecting their origins and present-day geographical location in Yunnan.

Alleles↗
PubMedDate not supplied

The distribution of Y chromosome haplogroups in the nationalities from Yunnan Province of China.

The genetic structure of 26 identified nationalities from Yunnan Province of China was studied using Y chromosome haplogroups. A total of 12 haplogroups were obtained in 1214 male samples from all the nationalities. The genetic relationships among 26 nationalities were studied. The ethnic groups were compared according to their different ancient lineages. The ancient lineages had their own characteristics in the distribution of Y chromosome haplogroups. Our results showed that Yunnan Province has great genetic diversity in its people. The ethnic groups differ from each other in the number of haplogroups and haplogroup frequencies. The genetic evidence was in agreement with the study of linguistic and historical records.

Alleles↗
PubMedDate not supplied

The epidemiology of childhood alopecia areata in China: a study of 226 patients.

To study the clinical and epidemiologic profile of childhood alopecia areata, we performed a survey in which a total of 226 childhood patients less than 16 years old were enrolled. Statistical analysis and heritability were performed using EPI INFO 6.0, SPSS10.0, and the Falconer method. The median age of onset was 10 years. The majority of patients (84.96%) presented with limited alopecia. The male : female ratio was 1.4:1. Boys appeared to have more severe involvement. The earlier the age of onset, the greater the severity of the disease. Sixty-seven patients (29.65%) had previous episodes of alopecia areata. Greater severity and longer duration were seen in the relapsing patients than in the primary patients. Six patients (2.65%) had an associated disease. A positive family history was reported in 25 patients (11.06%). The prevalence figures for alopecia areata in first-, second-, and third-degree relatives of the probands were 2.87%, 0.40%, and 0.13%, respectively. The heritabilities of AA in first-, second-, and third-degree relatives were 51.20%, 46.25%, and 25.65%, respectively. It can be speculated that the effect of genetic factors is important in the occurrence of this disease.

Adolescent↗
PubMedDate not supplied

Real-time detection of caspase-2 activation in a single living HeLa cell during cisplatin-induced apoptosis.

Caspase-2 is important for the mitochondrial apoptotic pathway, however, the mechanism by which caspase-2 executes apoptosis remains obscure. We carry out the first measurements of the dynamics of caspase-2 activation in a single living cell by a FRET (fluorescence resonance energy transfer) probe. Two FRET probes are constructed that each encoded a CRS (caspase-2 or caspase-3 recognition site) fused with a cyan fluorescent protein (CFP) and a red fluorescent protein (DsRed) (CFP-CRS-DsRed). Using these probes, we found that during cisplatin-induced apoptosis, caspase-2 activation occurred more slowly than did activation of caspase-3; additionally, caspase-2 activation was initiated much earlier than that of caspase-3.

Antineoplastic Agents↗
PubMedDate not supplied

Influence of drinking patterns of carbonated beverages on dental erosion.

As a hard tissue dental disease, dental erosion has a multifactorial etiology. The majority of dental erosion that originates from extrinsic sources is the result of dietary intake, particularly acidic beverages. Several preventive means have been proposed to minimize the damage to the dentition, including a reduction in the consumption of causative beverages and the adoption of a specific method of drinking, utilizing a straw instead of a cup. This article presents two cases involving the clinical and radiographic features of erosion lesions associated with chronic and excessive intake of acidic carbonated beverages. These examples embody how drinking patterns influence the formation of erosion lesions in various anatomic locations within the dentition. The clinical and radiographic evidence presented in this report cautions against the use of nonspecific terms, such as "cup versus straw," and instead suggests implementing a more precise description of the suggested method. In view of the extensive damage inflicted by the chronic, excessive intake of carbonated beverages, preventive measures are considered to be the only effective course of management. This article offers illustrative examples of erosion lesions associated with long-term excessive intake of carbonated beverages. The influence of the drinking method--that is, a straw positioned into the labial vestibule versus a cup--on the anatomic location of the erosion lesions will be demonstrated through clinical and radiographic evidence.

Adolescent↗